For those players of both Final Fantasy XI and Final Fantasy XIV who have been taking advantage of the subscription bonuses of playing both simultaneously, be prepared for a change. In preparation for the changes underway for Final Fantasy XIV: A Realm Reborn, Square Enix will be terminating all the subscription bonuses for individuals playing both games, such as the reduced monthly fee, special in-game items for XIV, and transfer of XI character names to XIV.

Let us know what you think of this planned change for XI and XIV over on the ZAM forums

From Playonline.com:

With the transition from the current version of FINAL FANTASY XIV to A Realm Reborn, FINAL FANTASY XI and FINAL FANTASY XIV simultaneous subscription bonuses will be terminated effective Saturday, September 29, 2012, at 23:59 (PDT).

Please make sure to redeem any items and transfer all of your FINAL FANTASY XI-related character names before the deadline.

Further details regarding simultaneous subscription bonuses.